Effects of the plant-derived hallucinogen salvinorin A on basal dopamine levels in the caudate putamen and in a conditioned place aversion assay in mice: agonist actions at kappa opioid receptors - Zhang,Y.; Butelman,E.R.; Schlussman,S.D.; Ho,A.; Kreek,M.J. (Psychopharmacology (Berl), 2005)